These steps will be easiest if you open a second Firefox window. To do that:
1) Look to the very top left of your screen.
2) Next to "Firefox" is the File tab.
3) Click on that, then New Window.
4) Follow the steps below in that window.
On the very top left of your screen find the word Firefox. Click on it.
On the left, click on Privacy & Security.
Spool down the page to the section headed Cookies and Site Data (A). Click the Manage Data button (B).
Type uflexi into the search box (A).
Click Remove All Shown (B).
Click Save Changes (C).
A pop-up will appear. Click Remove.
You’re done. Carry on using Calflexi: www.CalFLEXI.com